Which port does Gstreamer use?

I installed Gstreamer so that I could view media in SL, but I'm having no luck so far. But I haven't actually explicitly opened the port that Gstreamer uses, so it is probably still blocked.

Does anyone know which port Gstreamer uses? Google seems to find me no useful information on this.

I don't think it needs an incoming port, and probably grabs an arbitrary free one for the outgoing connection. I haven't had to unblock anything on either my software or hardware firewall, though I haven't viewed a lot of media either. The few thing's I've tried have worked fine. Are you behind a proxy that might disallow some types of outgoing connections?

As it's an URI which is played back, the server-side port will be 80 (HTTP), except another one is encoded in its URL (which is the case for a lot of audio and media streams). E.g. http://pink.neostreams.info:13178 uses server-side port 13178 and http://rs4.radiostreamer.de:8120 uses 8120. You can see the audio stream's URL by menu "World" > "About Land ...", tab "Media". To also see the media steam's URL, enable "View Admin Options" in the "Advanced" menu, before opening the "About Land" window. The steams can be different for each parcel, so the easiest is to allow all ports as long as the connection is initiated by your computer (i.e. as long as your computer acts as the client, not the server). Although this isn't the savest possible setup, it's the default one for most linux distributions, I guess.

Hmm. I'm using GuardDog, and I'm not sure it can cope with this. I'll have to check.

I suppose what I should do first is to try it without any firewall, just to see what happens then.

Any further advice would be very welcome.

I'd do just that. Some would argue this, but in my opinion, if you don't start any services you don't need and don't run untrusted applications, Linux can be considered secure without a firewall (for Desktop or Workstation usage -- on a server you might want to have some tighter control over what goes network wise and what doesn't). All the more if your system sits behind a NAT router, which is the case for most home networks.